Australia, as a signatory to the 1991 peace accord that ended decades of violence in Cambodia, had, Mr Rainsy said, an obligation to join the United States and the European Union and “push the Cambodian government of Hun Sen to reverse their repressive policies, to release political prisoners, to reinstate opposition members of parliament and to organise free and fair elections”.

“An election without opposition, it’s like the Liberals dissolving the Labor Party, putting the opposition leader in jail and then organising an election. You would not accept such a thing in Australia, you should not accept the same thing in Cambodia,” he said.

The politically sensitive refugee swap deal was signed in 2014 and cost Australia $40 million, but so far only six refugees have elected to resettle in Cambodia, and four of them have subsequently left according to UNSW’s Kaldor Centre for International Refugee Law.

Asked if this might be holding Canberra back from stronger criticism of strong man Hun Sen’s regime, Mr Rainsy agreed.

“Yes, this could be part of the problem because the current [Australian] government wants to seek to ensure the co-operation of the Cambodian government in implementing this very controversial refugee deal.”

Australian officials confirmed in December that Cambodia remained an option for refugee resettlement, despite Hun Sen’s latest crackdown.

He also suggested Australia should rethink the provision of aid money paid to the Cambodian government.

“Australia is a major donor [to Cambodia], but international assistance is like a sink hole for a country that is so corrupt. If Australia turns a blind eye to the death of democracy, and continues to pour assistance to Cambodia, using Australian taxpayers’ money, it is being wasted.”